Visualization of cell cycle arrest by X-irradiation in single Hela cells using fluorescent ubiquitination-based cell cycle indicator

Kaminaga, Kiichi; Noguchi, Miho; Narita, Ayumi; Sakamoto, Yuka; Kanari, Yukiko; Yokoya, Akinari

To explore X-irradiation effects on the mammalian cell cycle, we performed to track single cells as live cell images observed by the time-lapse imaging technique. HeLa cells with fluorescent ubiquitination-based cell cycle indicator (FUCCI) were used as irradiation sample cells to visualize cell cycle because their nuclei show different colors. We exposed X-rays to the HeLa-Fucci cells and observed them using a fluorescent microscope. We accumulated cells images every 20 min for 48 h and obtained evidences of cell cycle dynamics. The period of G1 and S/G2/(M) phase were analyzed and it was revealed that the irradiated cells were split in two populations, one showing similar cell cycle dynamics with that of unirradiated cells, and another showing modified cell cycle with a prolonged interval before progressing next cell cycle. The heterogeneous mixture of populations of irradiated cells might be involved in finally biological effects such as cell lethality.